INFLUENCE OF LIGHT WAVELENGTHS ON GROWTH OF TOMATO

An investigation of the influence of light wavelengths on growth rate and characteristics of chlorophyll-a on tomato plant has been done. The light wavelengths used in this study were 450 nm, 470 nm, 550 nm, 650 nm and 680 nm with the intensity of 1000 lux. Research conducted from the germination phase: the 0 until the 18th day and the vegetative phase: the 19th to the 53rd day. On germination phase, irradiation with wavelength of 680 nm has the greatest growth rate compared to other wavelengths, even greater than the germination under direct sunlight (or in the wild), especially on the 0 till the 8th day, the average growth rate obtained was approximately 1.11 cm/day. While in the vegetative phase, irradiation with wavelength of 680 nm was effectless, the greatest growth rate was obtained on irradiation with wavelength of 650 nm, e.g. 0.07 cm/day. This fact is also strengthened by the number of its chlorophyll-a is 7.784 mg /L. Based on those results obtained, it can concluded that the growth of tomato plant required various wavelengths as function of growth time.